March 6 (Reuters) - U.S. stocks traded lower on Tuesday, reversing from earlier gains prompted by signs of easing tensions in the Korean Peninsula and mounting pressure against tariffs proposed by President Donald Trump.

Weighing on the Dow and S&P 500 were health insurer UnitedHealth and plane maker Boeing, while Microsoft was the biggest drag on the Nasdaq.

“We’ve been moving a percent or more on many days, I don’t think there are any developments today that create the actions,” said Michael O’Rourke, chief market strategist at JonesTrading in Greenwich, Connecticut.

“People are just trading around their positions in the current environment.”

The CBOE Volatility index, better known as Wall Street’s fear gauge, rose for the first time in three days, last up 3.89 percent at 19.46.

South Korea said North Korea was willing to hold talks with the United States on denuclearization and will suspend nuclear tests while those talks are under way.

Trump’s threat last week to impose hefty tariffs on steel and aluminum sent markets sharply lower, but recovered as investors saw the threat as a negotiating tool to force Canada and Mexico to cede ground in the North American Free Trade Agreement (NAFTA) talks.

Stiff opposition to Trump’s plans from his own party also helped calm fears about a global trade war.

“This has all to do with the rationalization that tariffs issue is a negligible issue, in the sense that it’s a battle not a war,” said Matt Lloyd, chief investment strategist at Advisors Asset Management in Monument, Colorado.

At 11:31 a.m. EDT, the Dow Jones industrial average was down 140.65 points, or 0.57 percent, at 24,734.11, the S&P 500 was down 7.08 points, or 0.26 percent, at 2,713.86.

The Nasdaq Composite was down 6.99 points, or 0.1 percent, at 7,323.72.

Federal Reserve Bank of Dallas President Robert Kaplan told CNBC the base case on interest rate hikes has not changed and remains at three for the year, adding that the United States is either at or beyond full employment now.

Last month’s U.S. payrolls report showed wages growing at their fastest pace in more than eight years, fueling concerns that both inflation and interest rates would rise faster than expected that led to a steep selloff.

Investors are keenly waiting for the upcoming February jobs data due on Friday to gauge the strength of the labor market.

Qualcomm fell more than 3 percent after a U.S. government national security panel said it identified potential risks that warrant a full investigation of Broadcom Ltd’s $117 billion bid for the chipmaker. (Reporting by Ankur Banerjee and Sruthi Shankar in Bengaluru; Editing by Sriraj Kalluvila)